Invasive breast cancer

Invasive breast cancer occurs when abnormal cells from inside the milk ducts or lobules break out into nearby breast tissue.

Cancer cells can travel from the breast to other parts of the body through the blood stream or the lymphatic system. They may travel early in the process when a tumor is small or later when a tumor is large.

If breast cancer spreads, the lymph nodes in the underarm area (axillary lymph nodes) are the first place it’s likely to go.

Learn about treatment for invasive breast cancer.

Metastatic breast cancer

Metastatic breast cancer (also called stage IV or advanced breast cancer) is invasive breast cancer that has spread beyond the breast and axillary lymph nodes to other organs in the body (most often the bones, lungs, liver or brain).

Metastatic breast cancer is not a specific type of breast cancer, but rather the most advanced stage of breast cancer.

Learn about treatment for metastatic breast cancer.

Breast cancer in men

Breast cancer in men is rare, but it does happen.

Learn more about breast cancer in men.

Other types of cancer that occur in the breast

Most cancers that occur in the breast are breast cancers (breast carcinomas).

In rare cases:

• Other types of cancer such as lymphomas (cancer of the lymph system) and sarcomas (cancer of the soft tissues) can occur in the breast
• Cancers from other parts of the body can spread to the breast and mimic breast cancers

Other types of tumors in the breast can be benign (not cancer) or malignant (cancerous).

Because these cancers are not carcinomas, treatment is different than treatment for breast cancer.

For more information on other cancers that can occur in the breast, such as lymphomas, sarcomas and phyllodes tumors, visit the National Cancer Institute’s website.

*American Cancer Society. Cancer Facts and Figures 2019. Atlanta, GA: American Cancer Society, 2019.